#include <stdio.h>

int a = 10;
int b = 20;

void swap(int* a, int* b){
    int temp;
    temp = *a;
    *a = *b;
    *b = temp;
}

int main(){
    printf("a=%d,b=%d\n",a,b);
    swap(&a,&b);
    printf("a=%d,b=%d\n",a,b);

    //32位的机器，32bit位-4byte
    //64位的机器，64bit位-8byte
    printf("%zu\n",sizeof(int*));
    printf("%zu\n",sizeof(char*));
    printf("%zu\n",sizeof(short*));
    printf("%zu\n",sizeof(long*));
    printf("%zu\n",sizeof(float*));
    printf("%zu\n",sizeof(double*));
}